84 BLM/ Engine Temp Question

[84GNGary]

This is for my own knowledge and piece of mind. With the stock ecm & chip at idle my blm was 128, perfect. Now I preperation of installing an 87 ecm as soon as my TT chip arrives within the next week I added a few goodies. I installed an adj fpr and have it set for 38 psi with the line off at idle (stock injectors). I also installed a 160 stat. Now my blm's at idle are 133 to 141 and go down to 128 when given some gas. They were as high as 150 but I did find a vac leak. Now can the engine temp running 15 -20 cooler now effect the blm's. It has been very cool and the coolant temp is running between 160-170. I remember reading somewhere about the ecm has to see a certain coolant temp before it reacts properly. Next test is I am going to block off the radiator and get the temp up to 190 and see what she does.

With OTC in road mode before vac leak fixed
RPM - 725-800
o2 V - .25-.63 jumping
egr - on
BLM 150
MAF 004

In ALDL Mode before vac leak was fixed
o2 X - .001
TPS - .44
BLM 149
Intergrator - 119-131 jumping
LV8- 030
MAF - 005
RPM - 975
Iac - 42
o2V - .39-.62
Coolant Temp- 175

[kenmosher]

Coolant temp does affect fueling, and if the chip you are using has a normal operating temp set at 195 (stock), then it's going to be a bit on the rich side. No big deal and your new chip should correct the situation since it will be set for 160-165 degrees as normal operating temp.

BTW, the MAF is reading awfully low (normally you'll see about 6-7 g/s at idle. It may be your MAF is crapping out ...

[pfredricks]

It seems like IAC at 42 is at the high end.

Is it true that the IAC counts are spec'd at mid to low 20's? Or this different in ALDL mode?

http://www.gnttype.org/techarea/faq/IACresetscan.html

I've heard some guys like to run IAC counts at 10 or less.

[84GNGary]

I do have a new 87 maf (not a remanuf) that I will be using so that will eliminate one possile problem. I will just wait till I get the conversion done and see what the #'s are then. As always, thanks for good advice.

[84GNGary]

This is what I think is happening, so please correct me if I am wrong. With the stock ecm & chip the blm went from 128 to 150. At the same time when I did the other work I also added an aftermarket valve cover breather and plugged the hole on the TB intake that use to go into the old oil fill/valve cover breather. Now all the air going into the engine is accounted for by the maf. This includes even what was previously drawn out of the intake, through the engine to ventilate the crankcase into the pcv valve and back into the TB. So with this I am not gaining any air. Now by blocking off the port that use to go to the valve cover breather 100% of the air is now going directly into the engine intake. Now then I am still bring air in through the aftermarket valve breather through the pcv valve and into the TB. So this now extra air is not accounted for by the maf giving me a lean condition and a 150 blm. When I block off the pcv valve port on the vac block the blms drop to 134. It is reacting like I have a bad vacuum leak which I really don't it is just the stock chip does not know what is going on. Now I did get mt TT chip last night but I did not install it yet. I wanted to make sure everything was good before I proceeded any further. With the new chip and adjusting the fuel press this should offset the extra air and correct the a/f ratio and blms with hopefully drop to 128 once again.

[brad_padgett]

I do not think that this is your problem. I eliminated the whole stock oil fill tube(a real piece of crap) and put on a breather/ oil fill tube right on the valve cover. The engine ran fine on the stock chip and 85 MAF. Do you have an exhaust leak before the o2 sensor? Personally, I would put the TT chip and post new numbers. The stock chip is mentally handicapped. Brad

[84GNGary]

I just pulled and repaired both headers in late June (maybe 500 miles ago) put high temp copper rtv on and torqued to 38 ft lbs. So I doubt I have an exhaust leak. Also went over and checked and replaced vac lines and
ty wrapped them all. My o2 sensor is original at 43k.

After Installing the TT chip and drove around for 15 minutes. Restarted it later let it warm up and took these #'s. Have 43 psi with vac line off, coolant 164

Open loop
iac - 20
lv8 - 38
tps - .39 ( slightly low, went down when adjusting IAC)
int - 128
o2 - 551 mv
o2x- 30-42
maf - 4
blm - 140
rpm - 700-725 - sometimes go down to 600 then flares up to 800.

While idling at 1350 rpm - the only way to get blm to almost normal levels
iac - 27
lv8- 33
tps - .55
int - 129
o2 - 453mv
o2x - 16-24
maf - 8
blm - 131

Then let it return to normal idle everything pretty much the same as the first set of reading except the
o2 - 734mv sometimes it would drop to 450 then shoot back up but the blm stayed the same.
o2x - 0
int 128
blm 139

[Keller]

Doesn't the TurboTweak chip use an open loop idle?

Don't get too obsessive about the O2 numbers at idle. See how they are driving. There are 16 blocks on the map...

As long as the INT gets to 128-ish, the car is able to get to its happy place. Maybe some FP adjustment will be needed to trim things up a bit. I don't think things are too bad at the moment.

[brad_padgett]

I would get the TPS to .42-.44 at idle in park. The BLM is very close to be in range -118-138 (128 is perfect) at idle in park. I would increase fuel pressure and see if the BLM drops. It should. Every car is different when it comes to fuel pressure. Mine likes 45PSI with the line off. I also check BLM while driving. It should be in range. If it is high the chip is adding fuel. Good luck. Brad

[84GNGary]

I installed a new Denso O2 sensor on Tueday, reset the ecm and today the blm looked the best so far at 134. Now I am getting audible knocking when accelerating from idle at 10-20 mph, the ESC have been going up and I did catch it at 4.9 retard once. I am only getting about 11 lbs of boost too. FP is 43 @ idle with line off and had 54-55 at full boost. Now the O2's are staying around 800 steady at idle but they really drop off during accerlation followed by knocking. Here are my #'s from using Turbo Link, I did this several times and the o2 & blm dropping just before knock is consistant.

Also the Park/Neutral switch is not working, could that effect anything.

At Idle in drive frame 1

tps- .43
rpm- 675
int- 128
blm- 128
o2- 828
o2X- 0
maf- 8
iac - 48
esc- 2
rtd- 0
lv8- 38
coolant temp 165

@ 6mph frame 3

tps- 1.02
rpm- 1600
int- 130
blm- 115
o2- 156
o2X- 1
maf- 34
iac - 73
esc- 2
rtd- 0
lv8- 106

@ 11 mph frame 4

tps- 2.14
rpm- 2100
int- 128
blm- 115
o2- 70
o2X- 0
maf- 63
iac - 85
esc- 2
rtd- 0
lv8- 144

@ 19 mph frame 5

tps- 2.35
rpm- 2550
int- 128
blm- 115
o2- 86
o2X- 1
maf- 105
iac - 96
esc- 3
rtd- 4.9
lv8- 184

@ 29 mph frame 6

tps- 2.90
rpm- 3000
int- 128
blm- 115
o2- 801
o2X- 0
maf- 146
iac - 96
esc- 5
rtd- 2.8
lv8- 238
.

@47 mph frame 8

tps- 4.10
rpm- 3675
int- 128
blm- 128
o2- 820
o2X- 0
maf- 210
iac- 96
esc- 5
rtd- 0
lv8- 255

Oh yeah I have 93 octane and we did add about 1-2 gallon of octane booster to about 3/4 of a tank too and it still is knocking.
Any help is appreciated.